Watch-movement.



J.A.FRE UND. WATCH MOVEMENT.

APPLICATION FILED NOV. 10, 1911.

1 0 3 251 0 Patented June 3, 1913.

401 958??? I a. F INVIEI-JTOR W 422% A TTORNEY UNITED STATES PATENTOFFICE.

JOSEPH A. FREUND, 0F WALTHAM, MASSACHUSETTS, ASSIGNOR- TO THE KEYSTONEWATCH CASE COMPANY, OF PHILADELPHIA, PENNSYLVANIA, A

PENNSYLVANIA.

CORPORATION OF WATCH-MOVEMENT.

Application filed November 10, 1911.

To all 107mm it may concern.

Be it known that I, Josnrn A. FREUND, a citizen of the United States,and a resident of altham, in the county of Middlesex and State oflvlassachusetts, have made and invented certain new and usefulImprovements in lVatch-h fovements, of which the following is aspecification.

My invention relates to an improvement in watch movements, and moreparticularly to that part or portion thereof usually known and referredto by those skilled in this particular art as the impulse roller, orimpulse table, the objectof the same being to provide a roller whichshall be free from the many objections heretofore urged against theordinary type or construction thereof. In the production of a roller ortable for this purpose, it is usually shaped or formed, and after beingpunched or drilled, is subjected to heat treatment for the purpose ofimparting thereto the necessary hardness. It frequently happens that inhardening the article it is cracked or bro-ken, due to the unequalexpansion and contraction of the metal of which the roller is formed.Furthermore, in forcing the roller onto the balance staff, it frequentlycracks from the center outwardly not only during the operation ofdriving the hardened roller onto the staff, but in many instances, weeksand sometimes months later, due to the constant strain imposed on themetal of which the roller is formed by the tight and driving fit of thestaff therein. When these cracks appear in the roller, the accuratetime-keeping qualities of the movement are destroyed, the movementrunning erratically, and frequently stopping. In order to overcome theseobjections, I have constructed a roller provided with a central openingfor the staff, and with one or more openings therein adjacent to thecentral opening, the walls surrounding the central opening into whichthe staff is driven being thereby rendered comparatively thin andelastic, and avoiding any and all danger of cracking the roller from thecenter to the periphery, and incidentally reducing the weight of theroller to a considerable extent, a feature so much desired, andabsolutely essential, to secure the accurate time-keeping qualities in awatch movement. By so constructing the roller, it will be understoodthat in driving the staff into the central Specification of LettersPatent.

Patented June 3,1913.

Serial No. 659,462.

opening, should it happen that the walls of the opening be broken orcracked, such break or crack would extend only from the center to thenearest adjacent opening, and not entirely to the periphery of theroller, thereby avoiding to a large extent the destruction of thetime-keeping qualities of the movement. Again, by reason of theprovision of the several openings in the roller, the liability ofcracking the roller during the operation of heat treatment is materiallylessened, the bulk of the metal between the central opening andperiphery being materially reduced, and permitting the even distributionof heat throughout the entire article.

A roller involving the features above described is illustrated in theaccompanying drawings, wherein Figure 1 shows a plan View thereof; Fig.2 is a view in side elevation of the roller mounted on the balance staffemployed in a double roller movement; Fig. 3 is a plan view of a rolleror table as ordinarily constructed and shown with a crack thereinextending from the central opening to the periphery; Fig. at is aview inside elevation showing the roller, illustrated in Fig. 3, assembled witha balance staff as employed in a single roller movement.

Referring to the drawings, A represents an impulse roller or table madeof the usual diameter and thickness and provided with a central openingB for the reception of a balance staff G, and having secured therein animpulse or jewel pin D. In thisroller or table I form holes or openingsE, preferably extending entirely through the roller, and between thecentral opening and the periphery of the table, the walls F separatingthe central opening B, and the outer openings E, being renderedcomparatively thin and elastic, the metal separating the severalopenings in the roller being such that the heat during the operation ofhardening the metal can readily and evenly penetrate the same.

The walls F being comparatively thin, as above described, will permit ofthe driving of the roller onto the balance staff O without danger ofcracking, and should, perchance, such occur, the crack will extend onlyfrom the central opening B to the adjacent opening E, and not entirelyto the periphery, as indicated at G in Fig. 3.

When the metal of the roller is cracked from the central opening to theperiphery, the perfect balance of the roller is destroyed, causing themovement to run erratically and at times to stop. Particularly is suchcracking of the roller harmful in the case of a single roller movementas illustrated in Figs. 3 and 1, due to the fact that the guard pin H,secured to the pallet lever I, comes in contact with the periphery ofthe roller or table K, and striking against the cracked portion of theperiphery of the roller as the latter oscillates, entirely destroys theaccuracy of the movement.

In my improved roller, this objectionable result is avoided, as a slightcrack extending from the central opening B to an outer opening E (Fig.1), should such occur, does not to any appreciable extent destroy thebalance of the roller.

lVhat I claim is For use in a watch movement, an impulse roller providedwith a central opening, a balance start tapered to be driven into saidopening to form a force fit, portions of the metal of said rollerbetween the periphery thereof and said central opening being re movedthereby forming a continuous and elastic wall around said opening andpermitting said balance stafi to be assembled with said roller withoutdanger of cracking I the latter.

Signed at Waltham, in the county of Middlesex and State ofMassachusetts, this sixth day of November A. D. 1911.

JOSEPH A. FREUND.

Witnesses:

W. C. Cook W. B. MEHL.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents. Washington D. G.

